| Ageva Limited | Hospitality | 2020 |
| Agoo Consulting Ltd | Information & communication | 2025 |
| AGS Consultancy London Ltd | Information & communication | 2019 |
| AGS Properties London Limited | Real estate | 2025 |
| Ahaa Properties Ltd | Real estate | 2021 |
| Ahaa Travel Ltd | Administrative & support | 2025 |
| Ahadi Partner Ltd | Wholesale & retail | 2021 |
| Ahi&Co Limited | Hospitality | 2023 |
| AHK Trading Limited | Hospitality | 2023 |
| Ai-Rash Homes Ltd | Real estate | 2025 |
| Aidant Ltd | Professional & scientific | 2025 |
| Air Power Group Ltd | Manufacturing | 2025 |
| Air Power Solutions Ltd | Manufacturing | 2023 |
| Air Scooters Ltd | Wholesale & retail | 2021 |
| Airsome Ltd | Construction | 2024 |
| Airwade Limited | Manufacturing | 2013 |
| AIT Consulting Solutions Limited | Information & communication | 2025 |
| AJ Pro Construct Ltd | Construction | 2023 |
| AJ Tech Innovations Limited | Construction | 2023 |
| AK Electricity Ltd | Construction | 2014 |
| AK M&E Consulting Ltd | Construction | 2020 |
| Akam Property Ltd | Real estate | 2019 |
| AKC International Solutions Ltd | Administrative & support | 2014 |
| AKF 1 Limited | Administrative & support | 2015 |
| Akfa Properties Ltd | Real estate | 2026 |
| Aksaray Vadi Limited | Hospitality | 2015 |
| Albermarle Studio Limited | Information & communication | 2026 |
| Alclin (UK) Limited | Professional & scientific | 2010 |
| Alex Auto Care Ltd | Wholesale & retail | 2022 |
| Alexg Trans Ltd | Transport & logistics | 2024 |
| ALI UK Limited | Hospitality | 1998 |
| ALL Garage Roof Ltd | Water & waste | 2025 |
| ALL Parcel Shipping Limited | Transport & logistics | 2023 |
| ALL Stars Chauffeur Ltd | Transport & logistics | 2022 |
| ALL Stars Enterprise Ltd | Other services | 2024 |
| ALL Steels ALL Designs Ltd | Manufacturing | 2018 |
| Alliance Assets Limited | Real estate | 2013 |
| Alliance Healthcare (Distribution) Limited | Wholesale & retail | 1997 |
| Alliance Healthcare Management Services Limited | Administrative & support | 2009 |
| Alokdrishti LLP | | 2023 |
| Alpha Glass London Ltd | Construction | 2019 |
| Altaf's Kitchen Ltd | Manufacturing | 2021 |
| Altien Limited | Information & communication | 1997 |
| ALX Studio Ltd | Professional & scientific | 2024 |
| Alzee Properties Ltd | Real estate | 2025 |
| Amanda Watson Limited | Professional & scientific | 2015 |
| Amazing Fish Ltd | Hospitality | 2017 |
| Ameni Limited | Wholesale & retail | 2024 |
| AMI Digital Limited | Manufacturing | 2007 |
| Amina Albeyatti Ltd | Health & social care | 2018 |
| AMS Building Solutions Ltd | Construction | 2023 |
| Amu's TEC Ltd | Information & communication | 2014 |
| ANA G Properties Ltd | Real estate | 2026 |
| Analogue Studio Ltd | Professional & scientific | 2022 |
| Andinos Wholesale Ltd | Wholesale & retail | 2023 |
| Andrzej & Radek Home Improvements Ltd | Construction | 2025 |
| Andyman Property Services Ltd | Administrative & support | 2011 |
| Angel Assist Ltd | Construction | 2021 |
| Animal Basics Ltd | Other services | 2026 |
| Anitass Limited | Real estate | 2009 |
| Anthony's Haven Holdings Limited | Real estate | 2024 |
| Anthony's Prose Press Limited | Information & communication | 2024 |
| Anyone UK Ltd | Wholesale & retail | 2024 |
| Anything Goez Productions Ltd | Arts & recreation | 2017 |
| AO Motors Surrey Ltd | Wholesale & retail | 2025 |
| Apco Services Ltd | Construction | 2023 |
| Apptown Limited | Information & communication | 2022 |
| APT Vehicle Solutions Ltd | Administrative & support | 2015 |
| Aqua Broadcast Limited | Manufacturing | 2020 |
| Aram Marketing Limited | Wholesale & retail | 2021 |
| Arawa Residential Limited | Real estate | 2020 |
| ARB GAS Ltd | Construction | 2026 |
| Arbrook Hall Management Company Limited | Households | 2001 |
| Arch Financial Services Ltd | Financial services | 2021 |
| Archispace Interiors Ltd | Professional & scientific | 2025 |
| Archon International Limited | Health & social care | 2025 |
| Arcrange Ltd | Real estate | 2023 |
| Arham.M Ltd | Wholesale & retail | 2026 |
| Armj Estates Limited | Real estate | 2022 |
| Armorgie Limited | Wholesale & retail | 2024 |
| Arnold HR Consulting Limited | Administrative & support | 2013 |
| Arora Associates Limited | Professional & scientific | 2015 |
| Artium Property Services Ltd | Construction | 2024 |
| Asbestos Removal Ltd | Water & waste | 2024 |
| Asgaak Propery LT Ltd | Real estate | 2026 |
| Asgaak Propery Ltd | Real estate | 2026 |
| Ash&Milly Limited | Real estate | 2023 |
| Ashlyns Way Management Company Ltd | Households | 1986 |
| Ashtead Lodge Management Co Limited | Households | 2007 |
| Ashton Place (Chessington) Management Company Limited | Households | 2006 |
| Ashville Fire Solutions Ltd | Professional & scientific | 2025 |
| ASK International Limited | Wholesale & retail | 2007 |
| Asling Developments Ltd | Real estate | 2026 |
| Aspect Brickwork Ltd | Construction | 2023 |
| Aspect Maintenance Group Limited | Construction | 2021 |
| Aspect Maintenance Services Limited | Construction | 2004 |
| Aspire Design & Build Developments Limited | Real estate | 2023 |
| Aspire Dwellings Limited | Real estate | 2022 |
| Assidian Limited | Information & communication | 2003 |
| Assure Wealth Group Ltd | Real estate | 2026 |